Insight into the role of grafting density in the self-assembly of acrylic acid-grafted-collagen.

Side chain modification of collagen provides an attractive way to enhance their structure and functions, which is highly desirable for the development of promising biomaterials. However, the impact of structural change of side chains on the intrinsic self-assembly property of collagen was always ignored. Here, a series of acrylic acid-grafted-collagen (AA-g-Col) with different grafting density were prepared to explore the impact of side chain structural variation on the self-assembly of collagen. The results showed that excessive grafting density would weaken or even disappear the self-assembly property of AA-g-Col, but only affects the triple helix to a minor extent. Compared to pristine collagen, the mechanical property and cytocompatibility of AA-g-Col based matrices also deteriorated, along with the increase of grafting density. Therefore, this work contributed a new insight into the importance of grafting density for the study of modified collagen, which would be helpful for the design of optimized formulate collagen-based hybrid materials with both additional novel functions and tissue-mimicking fibrillary structures.